/*
 * Copyright (C) 2014 Traphandler
 * Copyright (C) 2014 Free Electrons
 * Copyright (C) 2014 Atmel
 *
 * Author: Jean-Jacques Hiblot <jjhiblot@traphandler.com>
 * Author: Boris BREZILLON <boris.brezillon@free-electrons.com>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 as published by
 * the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 * You should have received a copy of the GNU General Public License along with
 * this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/of_graph.h>

#include <drm/drmP.h>
#include <drm/drm_panel.h>

#include "atmel_hlcdc_dc.h"

/**
 * Atmel HLCDC RGB connector structure
 *
 * This structure stores RGB slave device information.
 *
 * @connector: DRM connector
 * @encoder: DRM encoder
 * @dc: pointer to the atmel_hlcdc_dc structure
 * @panel: panel connected on the RGB output
 */
struct atmel_hlcdc_rgb_output {
        struct drm_connector connector;
        struct drm_encoder encoder;
        struct atmel_hlcdc_dc *dc;
        struct drm_panel *panel;
};

static inline struct atmel_hlcdc_rgb_output *
drm_connector_to_atmel_hlcdc_rgb_output(struct drm_connector *connector)
{
        return container_of(connector, struct atmel_hlcdc_rgb_output,
                            connector);
}

static inline struct atmel_hlcdc_rgb_output *
drm_encoder_to_atmel_hlcdc_rgb_output(struct drm_encoder *encoder)
{
        return container_of(encoder, struct atmel_hlcdc_rgb_output, encoder);
}

static void atmel_hlcdc_rgb_encoder_enable(struct drm_encoder *encoder)
{
        struct atmel_hlcdc_rgb_output *rgb =
                        drm_encoder_to_atmel_hlcdc_rgb_output(encoder);

        if (rgb->panel) {
                drm_panel_prepare(rgb->panel);
                drm_panel_enable(rgb->panel);
        }
}

static void atmel_hlcdc_rgb_encoder_disable(struct drm_encoder *encoder)
{
        struct atmel_hlcdc_rgb_output *rgb =
                        drm_encoder_to_atmel_hlcdc_rgb_output(encoder);

        if (rgb->panel) {
                drm_panel_disable(rgb->panel);
                drm_panel_unprepare(rgb->panel);
        }
}

static const struct drm_encoder_helper_funcs atmel_hlcdc_panel_encoder_helper_funcs = {
        .disable = atmel_hlcdc_rgb_encoder_disable,
        .enable = atmel_hlcdc_rgb_encoder_enable,
};

static void atmel_hlcdc_rgb_encoder_destroy(struct drm_encoder *encoder)
{
        drm_encoder_cleanup(encoder);
        memset(encoder, 0, sizeof(*encoder));
}

static const struct drm_encoder_funcs atmel_hlcdc_panel_encoder_funcs = {
        .destroy = atmel_hlcdc_rgb_encoder_destroy,
};

static int atmel_hlcdc_panel_get_modes(struct drm_connector *connector)
{
        struct atmel_hlcdc_rgb_output *rgb =
                        drm_connector_to_atmel_hlcdc_rgb_output(connector);

        if (rgb->panel)
                return rgb->panel->funcs->get_modes(rgb->panel);

        return 0;
}

static int atmel_hlcdc_rgb_mode_valid(struct drm_connector *connector,
                                      struct drm_display_mode *mode)
{
        struct atmel_hlcdc_rgb_output *rgb =
                        drm_connector_to_atmel_hlcdc_rgb_output(connector);

        return atmel_hlcdc_dc_mode_valid(rgb->dc, mode);
}

static const struct drm_connector_helper_funcs atmel_hlcdc_panel_connector_helper_funcs = {
        .get_modes = atmel_hlcdc_panel_get_modes,
        .mode_valid = atmel_hlcdc_rgb_mode_valid,
};

static enum drm_connector_status
atmel_hlcdc_panel_connector_detect(struct drm_connector *connector, bool force)
{
        struct atmel_hlcdc_rgb_output *rgb =
                        drm_connector_to_atmel_hlcdc_rgb_output(connector);

        if (rgb->panel)
                return connector_status_connected;

        return connector_status_disconnected;
}

static void
atmel_hlcdc_panel_connector_destroy(struct drm_connector *connector)
{
        struct atmel_hlcdc_rgb_output *rgb =
                        drm_connector_to_atmel_hlcdc_rgb_output(connector);

        if (rgb->panel)
                drm_panel_detach(rgb->panel);

        drm_connector_cleanup(connector);
}

static const struct drm_connector_funcs atmel_hlcdc_panel_connector_funcs = {
        .dpms = drm_atomic_helper_connector_dpms,
        .detect = atmel_hlcdc_panel_connector_detect,
        .fill_modes = drm_helper_probe_single_connector_modes,
        .destroy = atmel_hlcdc_panel_connector_destroy,
        .reset = drm_atomic_helper_connector_reset,
        .atomic_duplicate_state = drm_atomic_helper_connector_duplicate_state,
        .atomic_destroy_state = drm_atomic_helper_connector_destroy_state,
};

static int atmel_hlcdc_check_endpoint(struct drm_device *dev,
                                      const struct of_endpoint *ep)
{
        struct device_node *np;
        void *obj;

        np = of_graph_get_remote_port_parent(ep->local_node);

        obj = of_drm_find_panel(np);
        if (!obj)
                obj = of_drm_find_bridge(np);

        of_node_put(np);

        return obj ? 0 : -EPROBE_DEFER;
}

static int atmel_hlcdc_attach_endpoint(struct drm_device *dev,
                                       const struct of_endpoint *ep)
{
        struct atmel_hlcdc_dc *dc = dev->dev_private;
        struct atmel_hlcdc_rgb_output *output;
        struct device_node *np;
        struct drm_panel *panel;
        struct drm_bridge *bridge;
        int ret;

        output = devm_kzalloc(dev->dev, sizeof(*output), GFP_KERNEL);
        if (!output)
                return -EINVAL;

        output->dc = dc;

        drm_encoder_helper_add(&output->encoder,
                               &atmel_hlcdc_panel_encoder_helper_funcs);
        ret = drm_encoder_init(dev, &output->encoder,
                               &atmel_hlcdc_panel_encoder_funcs,
                               DRM_MODE_ENCODER_NONE, NULL);
        if (ret)
                return ret;

        output->encoder.possible_crtcs = 0x1;

        np = of_graph_get_remote_port_parent(ep->local_node);

        ret = -EPROBE_DEFER;

        panel = of_drm_find_panel(np);
        if (panel) {
                of_node_put(np);
                output->connector.dpms = DRM_MODE_DPMS_OFF;
                output->connector.polled = DRM_CONNECTOR_POLL_CONNECT;
                drm_connector_helper_add(&output->connector,
                                &atmel_hlcdc_panel_connector_helper_funcs);
                ret = drm_connector_init(dev, &output->connector,
                                         &atmel_hlcdc_panel_connector_funcs,
                                         DRM_MODE_CONNECTOR_Unknown);
                if (ret)
                        goto err_encoder_cleanup;

                drm_mode_connector_attach_encoder(&output->connector,
                                                  &output->encoder);

                ret = drm_panel_attach(panel, &output->connector);
                if (ret) {
                        drm_connector_cleanup(&output->connector);
                        goto err_encoder_cleanup;
                }

                output->panel = panel;

                return 0;
        }

        bridge = of_drm_find_bridge(np);
        of_node_put(np);

        if (bridge) {
                output->encoder.bridge = bridge;
                bridge->encoder = &output->encoder;
                ret = drm_bridge_attach(dev, bridge);
                if (!ret)
                        return 0;
        }

err_encoder_cleanup:
        drm_encoder_cleanup(&output->encoder);

        return ret;
}

int atmel_hlcdc_create_outputs(struct drm_device *dev)
{
        struct device_node *ep_np = NULL;
        struct of_endpoint ep;
        int ret;

        for_each_endpoint_of_node(dev->dev->of_node, ep_np) {
                ret = of_graph_parse_endpoint(ep_np, &ep);
                if (!ret)
                        ret = atmel_hlcdc_check_endpoint(dev, &ep);

                if (ret) {
                        of_node_put(ep_np);
                        return ret;
                }
        }

        for_each_endpoint_of_node(dev->dev->of_node, ep_np) {
                ret = of_graph_parse_endpoint(ep_np, &ep);
                if (!ret)
                        ret = atmel_hlcdc_attach_endpoint(dev, &ep);

                if (ret) {
                        of_node_put(ep_np);
                        return ret;
                }
        }

        return 0;
}